Don't Frown, Just Smile
by Gundam-Knight-Chris
Summary: A one-shot 'What-if' theory if I was summoned as a Heroic Spirit in the Fourth Holy Grail War.


**What's up, everyone! This is GKC here bringing you my own version of Fate/Zero with a special guest star. Consider this my New Years Eve present. Also, this is a one-shot so it'll all depend if I'll continue it or not.**

 **Now let's get this party started… BEGIN!**

* * *

 **Don't Frown, Just Smile**

* * *

 **Einzbern Castle**

Kiritsugu Emiya, also known as the Magus Killer, was preparing for the Holy Grail War along with his wife, Irisviel von Einzbern. The Japanese man had sought to save the world and grant it true peace so that his family may live happily in a world without pain and suffering.

The Einzbern family had managed to collect one of the greatest artifacts in the use for their war. Avalon, the Scabbard of King Arthur. With that as the catalyst, the Einzberns would have the greatest warrior for the Saber Class and procure an edge in the war. Kiritsugu had prepared all the necessary requirements for the ritual in order to summon the King of Knights.

The Magus Killer had performed the incantation perfectly without hesitation as a brilliant flash of light came from the summoning circle as a figure rose from the crest.

It was a short woman with blonde hair done up in a bun and jade green eyes that burned with a fierce flame. She wore a blue battle dress that was covered in enchanted silver armor. Her eyes glanced at Kiritsugu.

"By your summoning, I have arrived. I ask of you, are you my Master?" The beautiful woman asked, surprising the two humans in the room.

Regaining his composure, the Magus Killer took a few steps towards the Servant and presented his Command Seals to her. "I am."

Then the woman spoke in firm tone. "Then our contract is complete. I, Servant Saber, will be your sword for this was and shall fight for you." To which, Kiritsugu was about to ask for Saber's identity when Irisviel yelped quite audibly, forcing the Master and Servant to look at the albino woman in surprise.

The white-haired woman started to contort in pain as she held her left hand. Emiya's eyes widened in shock when he noticed the all too familiar signs of a Command Seal as the summoning circle glowed once more.

Saber immediately readied her invisible sword, shouting at her Master and the woman, "Stay behind me! We know not who comes here!" Kiritsugu and Irisviel nodded in agreement and stood behind the Servant of the Sword.

The Magus Killer's mind ran in circles at the impossibility happening before him. _'How? How could this be? We only meant to summon one Servant, not two!'_ He thought frantically as the glow ceased then a figure walked out of the light.

The figure was revealed to be a tall man, who had the face of a teenager. He had wild, curly brown hair with dark brown eyes, a slightly tanned complexion, and handsome facial features. He looked a bit skinny as well but his muscles were firm and powerful. He wore a black leather jacket with the zipper opened to reveal a red shirt with a black demon head image, black slacks, black combat boots, and a pair of black fingerless hard-knuckle gloves. Sitting on the bridge of his nose was a pair of black-rimmed glasses.

"Identify yourself, Servant! Who are you!?" Saber shouted at the stranger, who merely blinked with a bored look before glancing at Irisviel.

"So, you're my Master for this war? A shame for someone as cute as you." The Servant spoke in a soft, yet firm voice. The Homunculus blushed a cherry red at the compliment while Kiritsugu's eye twitched in brief annoyance.

"Wait, Saber, that is my Servant!" Irisviel stopped the Servant of the Sword from trying to assault the unknown man. "Somehow I've managed to summon him here to assist us!"

The King of Knights glanced at the albino then back at the brown-haired man, who nodded in confirmation. Saber lowers her sword but remained on guard all the same towards the unknown Servant.

"Well, now that _that's_ out of the way, I suppose I should introduce myself." The glasses-wearing Servant stated before lightly coughing into an enclosed fist then gave the three a blank expression. "I am Servant Caster, here to fight by your side. Since you've already shown me your Command Seals then that means our contract has been signed. Which means you have my services until we either win or I die."

Irisviel smiled at Caster then began to check his stats only for her eyes to nearly bug out of their sockets at what she saw. "Are you sure that you're a Caster?" She asked, her jaw comically reaching the floor.

"That's what I was summoned as," Caster's left eye twitched in annoyance. "Not like I wanted to be this lame ass Class but the Throne thought my stats as other classes would be deemed too OP." He shrugged in boredom.

Emiya and Saber looked at Irisviel in confusion. "Iri, what is it? What are his stats?" The Magus Killer asked.

The albino looked at her husband, recovering from her surprise. "H-He has an E-rank Mana!"

The Master of Saber as well as the Servant's eyes widened in disbelief then looked at Caster.

"Yeah, in my life, I never had a speck of magic in my blood or even knew any." The brown-eyed Servant explained. "The Grail just has a way of being a complete fucking troll."

Shaking off the shock, Kiritsugu looked at the male Servant with analyzing eyes. "So what are we supposed to call you since it is quite obvious that your clothing is modern and you seem to not have a place in history in the past."

"You're right, my legend is actually from the future." Caster replied. "I've been called many names but the one I liked the most were the initials of my most famous title, GKC."

Saber blinked, owlishly. "What is that supposed to mean, Caster?" She asked, perplexed.

"Well, my dear King of Knights. It's short for a very long name but I will not divulge it as of now for my name is not important at the moment." Caster answered while winking at Saber, who had a small blush on her cheeks despite her stoic stature.

* * *

 **The Next Day**

Saber watched as Kiritsugu played with his daughter, an adorable girl named Illyasviel von Einzbern. The small girl was also running while giggling as a small Yorkie Terrier with brown and black fur chased after her, barking playfully. The small dog came from one of Caster's Noble Phantasms, _Family Forever_.

"Find it strange to see a stone, cold man like Kiritsugu actually smile and play with his daughter, Saber?" Caster asked, standing next to the King of Knights with his jacket gone.

"I did not expect this type of behavior from my Master, Caster." Saber answered, truthfully.

"Even though that guy puts up a cold, emotionless facade, he still has a kind heart that seeks peace." The Servant of Magic responded. "A good man who has to make the hard choices. It's almost cruel if you think about it."

"Precisely Caster, Kiri is a kind man but he does not interact with you two because he's upset at the fact that both of you were young when you took up your duties." Irisviel spoke up as she entered the room with tea which both Servants gratefully accepted.

"Well, I wouldn't say I was young when I took up my duties but it happened nonetheless." Caster nodded, sipping his tea. "In which case, me and Saber here will never be able to get along with Emiya since we are willing to sacrifice so much for others that we basically shoulder the burden ourselves."

The albino woman decided to change the subject. "So what do you think of our chances of winning the Holy Grail War?" She asked, honestly wanting to hear what the two Servants thought.

"In all honesty, I don't know. I'm not much of a Caster but I'll do my damnest to try and support Saber as well as you and Emiya, Master." Caster vowed to which Irisviel had a feeling of hope swell in her chest while Saber smiled in appreciation.

"Thank you so much, Caster!" Irisviel squealed as she hugged her Servant, who had a small blush of embarrassment on his face. Saber, looking at the sight, actually giggled like a schoolgirl at the Master and Servant pair.

* * *

 **Few Days Later - Fuyuki City**

Irisviel was being suffocated by the former Master of Assassin, Kirei Kotomine. She had deeply regretted taunting the man now that she realized that her Servant gave her a second chance to live with her family. A lone tear cascaded down her cheek. _'Caster, forgive me…'_ She thought, accepting her fate.

A familiar voice called out to her. "Get your filthy hands off of her, you bastard!" Caster shouted as he kicked the priest away, sending him crashing into a wall.

The albino woman looked upon her savior with tear-stricken eyes as she wrapped her arms around Caster's waist, sobbing into his chest.

"Shh, it's alright. I'm here now." Caster calmed his Master's nerves, a soft grin on his face as he stroked her snow white hair in a form of comfort.

"Caster, please, protect Kiri and Saber…" Irisviel managed to utter out while hiccuping a bit. "I don't want anyone else to die."

The brown-haired Servant nodded. "Consider that my promise to you, Master." He said, standing up while carrying Irisviel in a bridal carry then taking her out of the theater to the Emiya Residence.

* * *

 **One Hour Later**

Caster held his injured arm, his clothing was tattered and blood dripped down his forehead. Standing before him was Archer also known as Gilgamesh, the King of Uruk. Saber was busy fighting Berserker so it was all down to the Servant of Magic against the Servant of the Bow.

"Well, mongrel, you've put up an entertaining display for me and for that, I shall grant you the great honor of dying by the hand of your King." Archer stated with an arrogant grin.

Caster spat out a bit of blood while glaring at the golden Servant. "King? I serve no one especially not some arrogant child who throws a temper tantrum everywhere he goes."

Gilgamesh's grin turned into a scowl as his slitted red eyes glared at Caster. "You would dare insult your King, mongrel?! You shall rot in the dirt like the worthless dog you are." With that said, golden ripples opened revealing hundreds of Noble Phantasms all aimed directly at the brown-haired Servant.

Caster huffed as he gripped his cracked glasses then tossed them to the ground. "That's where you're wrong, Archer. For you have yet to see my ultimate Noble Phantasm." He started as crimson red markings appeared on his face then all over his body.

"Nothing you do will save you now, mongrel." Archer sneered as he fired Phantasm after Phantasm at Caster.

Before the vast array of Noble Phantasms could strike him, Caster uttered out two words. " _Creator's Will!_ " Then a large cyan blue holographic shield appeared and absorbed all of Archer's attacks.

"Mongrel, you would dare defy your King?!" Archer yelled in vicious anger before he suddenly shook when he noticed the cold look upon the Servant of Magic's face.

"Shut the hell up already, you fucking cunt." Caster insulted before raising his hand up then snaps his fingers. In a flash of light, three separate robots appeared in front of Caster. One was a mixture of white, blue, and cyan with angel wings, another was slim and angular with black and gold armor, and the last was dragon-like with magenta and dark grey armor. "Angel, Stardust, Cosmic, take him down!" He ordered as the three robots flew at Gilgamesh with colored particles bursting out of their backs.

"Simple toys like these will not stop me!" Archer declared, bringing out his own ultimate Noble Phantasm, Ea.

"But that wasn't even my ultimate Noble Phantasm." Caster grinned darkly as he used the last of his prana for his greatest Phantasm. " _Ben and Andrew!_ " The moment the words left his mouth, two figures appeared by his side. Both possessing brown hair and dark brown eyes only they both seemed younger. The shortest wore a white hooded cloak and held a large greatsword in his hands. The tallest and larger of the two had on heavy armor while carrying a shotgun in his own hands.

"So, we finally get a chance to kick this punk's ass?" The shorter one asked in a voice similar but much more mellower than Caster's.

"Good, I hate this bitch ass prick anyways." The larger one said in a slightly deeper voice while cocking his weapon.

Caster grinned in anticipation as black armor encased his form and a katana appeared in his hands. "Well, bros, this could be our last fight together. So let's make it count." He stated with his younger siblings nodding in agreement as the three charge at Archer with fierce battlecries.

* * *

 **After Saber destroys the Holy Grail and the Great Fuyuki Fire passes**

Irisviel trotted through the destroyed city, hoping to find some remnant of her Servant after she felt Caster's prana levels begin to drop dangerously low.

Her red eyes scanned the terrain before they settled onto a lone figure kneeling, his body encased in dented black armor with various cuts on vital areas. "Caster!" Irisviel called out, running towards her Servant.

The figure stood up to full height as the black armor shattered away to reveal the torn clothing of Caster as he turned to Irisviel with a soft but tired grin. Blood dribbled down his lip as his wounds, grievous from the battle against Gilgamesh, began to take their toll on him. Golden particles began to fly off his body,

Irisviel stopped, her eyes widen in horror. "No…" She muttered as fresh tears appeared in her eyes. "Caster, you can't die!"

"Sorry, Master, but I neglected to tell you that using my ultimate Noble Phantasm drains me completely of my mana and with my low rank… I'm not able to stay in the physical world any longer especially when Archer finally wounded me seriously." Caster told the albino woman as his feet began to disappear.

"But I don't want you to leave me all alone!" Irisviel cried only for her Servant's arms to wrap her in a hug, a warm smile on his face. "Caster?"

"Don't cry anymore, Master. It's not something I like to see on a pretty lady," The Servant responded as he closed his eyes, his smile still on his face. "So smile, that way I can return to the Throne knowing that you'll still be the same free-spirited woman that I've come to respect and love."

Irisviel looked up at the face of her Servant, despite the tears falling down her pale cheeks she gave Caster a small smile.

"There you go. A smile suits you better than a frown." Caster chuckled as his form vanished into golden particles that floated into the air.

So passes the Caster of the Fourth Holy Grail War also known as Gundam-Knight-Chris or GKC for short.

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 **A/N: This oneshot was inspired by** _ **Infinite Paths**_ **by Lord Mist. Check it out, it's pretty cool.**

 **Now just to point out, I'm not actually that OP well unless I use my Imagination at a higher rank otherwise, any Servant that fought me would be fucked.**

 **I'll be putting my Servant stats up here as well so look forward to that. Also, think of this one-shot as a challenge to see if you guys can come up with your own self-Servant. Just don't make yourself too OP if you do it, otherwise it just kills the mood.**

 **Please review and comment but no flames or criticisms otherwise I'll tear your damn heart out and feed it to my dog.**

 **If you ignore the warning then I just don't give a flying fuck.**

 **Peace out, everyone!**

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Class: Caster

Master: Irisviel von Einzbern

True Name: Gundam-Knight-Chris

Titles: GKC, The Guy who doesn't give a fuck

Sex: Male

Height/Weight: 6'1" / 150 lbs

Alignment: Chaotic Neutral

Strength: D

Endurance: C

Agility: C

Mana: E

Luck: B

Noble Phantasm: A+

 _ **Class Skills-**_

Item Construction: E

The skill to manufacture magical items.

Despite being of the Caster class, he has a no skill level at this.

Territory Creation: C

The skill to build a special terrain that is advantageous to oneself as a magus.

While not a traditional Magus, Caster is still able to create a 'Temporary Workshop' from whatever enclosed space he stays in. It does not boost his Mana in anyway but it does provide him with weapons that he so desires.

 _ **Personal Skills-**_

Imagination: EX

The mental ability to create various objects in one's inner mind.

In his life, Caster has seen many things that gave him thousands of ideas and possibilities that were beneficial to his legend. When using one of his Noble Phantasms, this skill boosts his other skills up two ranks if it is EX Rank.

Eye of the Mind (True): B+

Heightened insight that was refined through experience.

Caster has been in situations in which his reaction was honed to near superhuman levels. While not being in many battles, Caster still has a miniscule chance of victory against his opponent.

Mystic Eyes: E

A spell inherent to the wielder's eyes that activates as soon as a person looks at them.

Caster's Mystic Eyes are known as the _Eyes of Perception_ , the crystallised eyes of a hawk that gives him enhanced eyesight, microscopic vision, and night vision. His eyes can also make out weak points in his opponents.

Charm: C

A skill that enchants those who look upon the wielder's face.

Caster was known as a heartthrob when he was alive. Female Heroic Spirits are greatly affected by this skill unless they have a higher Mana Resistance that is at least EX Rank.

 _ **Noble Phantasms-**_

Family Forever _"The Bonds of Loved Ones":_ B

Caster is able to summon members of his family as D or C Rank Heroic Spirits to aid him in battle. If one member of the family is killed, they cannot be brought back into the current Grail War that he is participating in.

Creator's Will _"The Imaginative Mind Unleashed"_ : EX

When this Noble Phantasm is activated, Caster is able to summon numerous creations that only he created with his mind as a B or A Rank Heroic Spirit or Noble Phantasm. Caster can only summon them if his mind was the one that originally visualized and gave them life. If his Imagination Rank is EX then this Noble Phantasm is guaranteed to summon an EX Rank Noble Phantasm or Heroic Spirit for Caster to use.

Ben and Andrew _"Brothers Unite"_ : EX

Caster can call upon his younger siblings to aid him in battle as, depending on his Servant Class, B, A, or EX Rank Heroic Spirits. If he fights together with his brothers, Caster's overall skill set increases to A+ Rank. Should one of his brothers fall in battle, his Rank diminishes by one. Using this will effectively drain Caster of all his Mana which will put him at risk of disappearing. This is his ultimate, yet dangerous Phantasm.


End file.
